Answer:
a) Kb = 10^-9
b) pH = 3.02
Explanation:
a) pH 5.0 titration with a 100 mL sample containing 500 mL of 0.10 M HCl, or 0.05 moles of HCl. Therefore we have the following:
[NaA] and [A-] = 0.05/0.6 = 0.083 M
Kb = Kw/Ka = 10^-14/[H+] = 10^-14/10^-5 = 10^-9
b) For the stoichiometric point in the titration, 0.100 moles of NaA have to be found in a 1.1L solution, and this is equal to:
[A-] = [H+] = (0.1 L)*(1 M)/1.1 L = 0.091 M
pKb = 10^-9
Ka = 10^-5
HA = H+ + A-
Ka = 10^-5 = ([H+]*[A-])/[HA] = [H+]^2/(0.091 - [H+])
[H+]^2 + 10^5 * [H+] - 10^-5 * 0.091 = 0
Clearing [H+]:
[H+] = 0.00095 M
pH = -log([H+]) = -log(0.00095) = 3.02
Four different substituents are required on a carbon atom for it to be chiral.
<h3>What is Chiral Carbons ?</h3>
The carbon atom which is attached with four different types of group of atoms or atoms is called Chiral carbon. Chiral molecules are non superimposable on their mirror images. Chiral carbon is also called asymmetric carbon.
Example:

In the above example we can see that carbon atom has 4 different group attached with it that is Br, Cl, H, CH₃.
Thus from the above conclusion we can say that Four different substituents are required on a carbon atom for it to be chiral.
Learn more about the Chiral carbon here: brainly.com/question/1195366
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Answer:
C.
Explanation:
Scientific notation is a way of writing small and large numbers. It is a way of expressing a standard form into a scientific form.